Topical administration of cyclosporin A in a solid lipid nanoparticle formulation.

Cyclosporin A (CsA)-loaded solid lipid nanoparticles (SLN) were developed for improved skin penetration. CsA-loaded SLN, prepared using a hot homogenization method, were nano-sized (about 73 nm) with a slightly negative surface charge (about -16 mV) and stable under physiological conditions regardless of CsA incorporation. In vitro permeation studies using murine skin mounted in the Franz-type vertical diffusion assembly revealed that the skin permeation efficiency of CsA-loaded SLN was 2-fold higher than that of CsA-oil mixture in viable skin. Furthermore, topically administered CsA-loaded SLN relieved symptoms of atopic dermatitis (AD) in an in vivo murine model of AD by decreasing the T helper (Th) 2 cell-related cytokines interleukin (IL)-4 and -5. These results suggest that SLN are effective drug carriers for topical delivery andthat CsA-loaded SLN can be therapeutically applied in allergy-related skin disorders.